Refrigerating apparatus



June 27, 1961 BOHN 2,990,111

REFRIGERATING APPARATUS Filed Sept. 22, 1959 P'.6 a A IN V EN TOR. Ma044.: J 50/10 Uni 2,990,111 REFRIGERATING APPARATUS Nicholas J. Bohn,Dearhorn, Mich., assignor to American Motors Corporation, Detroit,Mich., a corporation of Maryland Filed Sept. 22, 1959, Ser. No. 841,5473 Claims. (31. 230-232 My invention relates to a refrigerating apparatusand more particularly to hermetically sealed motor compressor units foruse in connection with such apparatus.

It is an object of the present invention to provide an improvedarrangement for quieting the operation of a hermetically sealed motorcompressor unit by reducing the transmittal of the operational noisesand sounds to the outside casing.

Another object of the present invention is to provide an improvedarrangement for the stirring and agitation of the oil or lubricantstored within the lower port-ion of the chamber formed by the outercasing that it will become mixed with refrigerant gases forming bubblesthroughout the entire body of the oil or lubricant whereby the bubbleswill cause to reduce the oil or lubricants ability to transmit theoperational noises and sounds of the motor-compressor unit to the outercasing.

Another object of the present invention is to provide a stirringarrangement for the oil or lubricant which is simple in construction,economical of manufacture and highly efficient in use.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing, wherein a preferred form of the present invention is clearlyshown.

FIG. 1 is a front view of a refrigerant compressor embodying features ofmy invention and showing a portion thereof broken away and parts thereofin cross section;

FIG. 2 is a vertical fragmentary view in cross section of my inventionand showing it attached to a crankshaft;

FIG. 3 is a side view of my invention with a part broken away;

FIG. 4 is a view taken along line 44 of FIG. 2;

FIG. 5 is a view taken along line 5-5 of FIG. 2; and

FIG. 6 is a diagrammatic view of a refrigerating system including acompressor embodying features of my invention.

Shown in the drawing is a motor-compressor unit 20 which comprises ingeneral a compressor 22 and an electric motor 24 mounted within a sealedcasing or shell 26.

The casing 26 consists of an upper shell 28 and a lower shell 30 whichare welded together by their flanges to form a sealed chamber 32.

The motor 24 and the compressor 22 are secured to a common casting 34 toform an assembled unit which is mounted by suitable springs 36 to theinner wall of the casing 26 in a vertically extending position withinthe sealed chamber 32.

The motor 24 includes a stator 38 that is secured on the casting 34 anda rotor 40 which is mounted upon a crankshaft 42.

The crankshaft 42 has a shaft section 44 that is journaled in a bearingsection 46 formed in the casting 34. The shaft section 44 extendsupwardly and outwardly from the bearing 46 and supports the rotor 40thereon. Adjacent the lower end of the bearing 46 the shaft is formedwith a crankarm 50 to which is connected one end of a connecting rod 52.The opposite end of the connecting rod 52 connects to a piston 54 whichoperates Patented June 27, 1961 chamber 32 into the cylinder 56. Therefrigerant is conducted from the chamber 32 towards the cylinder 56through a conduit 62. The valve plate is also provided with suitabledischarge valves (not shown) to control the flow of compressedrefrigerant vapors from the cylinder into the cylinder head. From thecylinder head the compressed refrigerant iiows through a conduit 64 forconduction through a connecting conduit 66, external of the casing 26,into a condenser 70 for cooling and condensing. The condensedrefrigerant is metered in its fiow from the condenser 70 by a smalldiameter conduit 72 for conduction into the evaporator 74. From theevaporator 74 the heat laden refrigerant vapors are returned to thechamber 32 through a conduit 76. The conduit 72 permits equalization ofpressures in the casing 26 and condenser 70 during the off phase of therefrigerating cycle.

A reservoir of oil or lubricant is maintained in the bottom of thechamber 32. As oil is a conductor of sound it is highly desirable thatthe oil be maintained at a level 82 which is preferably below the majorportion of the compressor and particularly the compressor body. With theoil level at 82 there is a minimum of contact with the compressor bodyso that there is reduced to a minimum the conduction of operationalnoises of the compressor through the oil or lubricant to the outercasing. How ever, even with the oil level at 82, particularly inhermetically sealed compressors, the oil or lubricant will be in somedirect contact with some projecting portion of the compressor, conduits,mufflers or the like from which undesirable sounds and noises aredirectly transmitted to the oil or lubricant for conduction thereby tothe outer casing. I

To reduce this transmittal of sound conduction through the oil orlubricant I have provided a pair of paddle members formed integral withan oil lifting device 102. The oil lifting device 102 is more fullydescribed and is the subject of a co-pending application for U.S.Letters Patent Serial No. 841,546, filed by Ralph W. Doeg on even dateherewith and assigned to the assignee of the present application.

Vaporous refrigerant is contained in the casing 26 and during theoff-phase of the refrigerating cycle some of the refrigerant vaporbecomes absorbed or impregnated in the body of lubricant due to theincrease in pressure in said casing.

Briefly the oil lifting device 102 comprises an inverted cone shapedbody which is secured tofor carry by the crankarm 50.. The cone shapedbody 110 is formed with a bore 112 extending inwardly from the base side1 14 of the cone to receive a downwardly projecting crankarm member 116.The cone is secured to the crankarm member 116 by a screw 117. The bore112 is off-centered in the cone from the cones axis, a distance equal tothe radius from the center of the crankanm to the axis of thecrankshaft, so that when the cone is mounted on the crankarm the axis ofthe cone is in direct alignment with the axis. of the shaft section 44of the crankshaft. The axis of the cone is a centerline from thetruncated apex 118 extending perpendicularly to the base side 114 of thecone.

Extending through the cone body 110 along the axis of the cone is acentral passageway 120 which has its inlet opening 122 in the apex 118and its outlet 123 in the base side 1114. The passage 120, from theentrance opening 122, has a side wall that inclines, as at. 124, towardsthe bore 112 to form an inclined of angular passage 126 whichcommunicates with a longitudinally directed passage 130 formed in thecrankshaft 42.

In operation as the crankarm rotates in an orbited path it will carrythe cone therearound but as the apex. 118 of the cone is aligned withthe axis of the shaft 44 it will rotate on a stationary axis andminimize any disturbance to the oilto permit its entrance into theopening 122. The lower end of the cone body extends below the oil level82 so that at all times the inlet opening 122 is submerged in the oil.The outlet 12.3 of the passage 120 is above the oil level 82. As thecone rotates, the oil entering the opening 122 is centrifugally liftedup the inclined side 124, or passageway 126, to enter the passage 130 ofthe crankshaft from which the oil is distributed to radial passageswhich further distributes the oil or lubricant to various points in thecompressor requiring lubrication.

As the lubricant or oil is subjected to centrifugal force to effect itslifting within the cones body this force will also cause any refrigerantmixed with the lubricant to become separated therefrom, and afterseparation the refrigerant will travel vertically upwardly through theaxial passage 120 to the outlet 123 for return to the chamber 32.

A circumferential recess or pocket 140 is formed in the bottom wall ofthe bore 114 which is in open commu nication with the inclinedpassageway 126. Dirt and other foreign particles that are in the oilwill be centrifugally separated therefrom to become trapped and remainlodged in the recess 140. The inclined side 124 is so arranged that thedirt particles will be centrifuged to pass into the recess 140 beforethe oil can enter the passage 132.

The paddles 100 are preferably formed integral with the cone body 110.The paddles are formed to extend radially outwardly from the cones bodyin diametrically opposed relation and preferably in alignment with theaxis of the cone. The paddles extend from the base of the conedownwardly to terminate at a point a short distance above the apex 124of the cone. The paddles extend above and below the oil level 82. Thoughthe paddles are shown as being widest in width at the lower end andtaper or narrow in width as they approach the cones base it will beapparent that other shapes and designs may be had. However, the paddlemust terminate a spatial distance above the opening 124 to prevent oildisturbance about the opening 124 which would interfere with theentrance of oil thereinto.

During the operation of the compressor the paddles will rotate about thestationary axis of the con The rotation of the paddles will agitate theoil or lubricant in manner to beat and trap refrigerant vapors from thechamber 32. The refrigerant vapors through the stirring action of thepaddles will be dispersed as bubbles throughout the body of. the storedlubricant. As the paddles keep stirring and agitating the lubricantthere will be a continuous mixing and releasing of refrigerant bubbleswhich will cause foaming on the surface of the lubricant. Also foamingtakes place by the reduction in pressure during the on-phase of therefrigerating cycle. The more refrigerant bubbles stirred into the oilthe greater will be the reduction in the oils ability to transmit soundby conduction to the casing.

By keeping the oil level whereby it is in minimal contact with thecompressor body, and keeping the oil stirred whereby refrigerant gaseswill mix as bubbles with the oil it has been found that there is aminimal of sound transmission through the oil body to the casing. Bythis reduction of sound transmittal through the oil the objectionablenoise transmittal from the casing is reduced to a minimum providing fora quieter operating unit.

Although only a preferred form of the invention has been illustrated andthat form described in detail, it will be apparent to those skilled inthe art that various modifications may be made therein without departingfrom the spirit of the invention or from the scope of the appendedclaims.

1. Refrigerating apparatus comprising a casing, a

sealed chamber formed by said casing and adapted to receive and toconduct refrigerant vapors therethrough, a body of liquid lubricantstored in said chamber, a compressor including a crankshaft mountedwithin said chamber, a motor Within said chamber operatively connectedto drive said crankshaft for operation of said compressor, paddle meansextending vertically from above said body of liquid lubricant downwardlyinto said body of liquid lubricant, and means for operatively connectingsaid paddle means externally to said crankshaft whereby the operation ofsaid crankshaft will rotate said paddle means to agitate the vaporousrefrigerant contained lubricant and to mix therewith refrigerant vaporsfrom said chamber and which vapors will be dispersed throughout the bodyof liquid lubricant as bubbles.

2. Refrigerating apparatus comprising a casing, a sealed chamber formedby said casing and adapted to receive and to conduct refrigerant vaporstherethrough, a body of liquid lubricant stored in the lower portion ofsaid chamber, a compressor including a crankshaft mounted to extendvertically within said chamber, said crankshaft having its lower endterminating a spatial distance above the level of liquid lubricantstored in said chamber, a motor within said chamber opcrativelyconnected to drive said crankshaft, a lubricant conducting membersecured to said crankshaft, said member extending from the lower end ofsaid crankshaft into and below the level of liquid lubricant and adaptedto conduct lubricant towards said crankshaft during the operation ofsaid crankshaft, paddle means carried by said memher, said paddle meansextending vertically from a spatial distance above and downwardly intothe body of liquid lubricant stored in said chamber and adapted toagitate the liquid lubricant to mix therewith refrigerant vapors fromsaid chamber and which vapors will be dispersed throughout the body ofliquid lubricant as bubbles.

3. Refrigerating apparatus comprising a casing, a sealed chamber formedby said casing and adapted to receive and to conduct refrigerant vaporstherethrough, a body of liquid lubricant stored in the lower portion ofsaid chamber, a compressor including a crankshaft mounted to extendvertically within said chamber, said crankshaft having a crankarm at itslower end and positioned a spatial distance above the level of liquidlubricant stored in said chamber, a motor within said chamberoperatively connected to drive said crankshaft, a lubricant conductingmember adapted to conduct lubricant during the operation of saidcrankshaft and including a vertically extending body section having anaxis in alignment with the stationary axis of said crankshaft and asection extending laterally from said vertical body section, means forsecuring said laterally extending section of said lubricant conductingmember to the lower terminable end of said crankarm, said vertical bodysection extending below said level of lubricant, an inlet opening insaid vertical body section below the level of lubricant, means providedin said lubricant conducting member to conduct lubricant towards andinto said crankarm from said inlet opening, paddle members carried bysaid vertical body section, said paddle members extending radiallyoutwardly from said body section, and said paddle members extending fromabove the level of lubricant to below said level of lubricant toterminate a spatial distance above said inlet opening.

References Cited in the file of this patent UNITED STATES PATENTS1,295,491 Hazard Feb. 25, 1919 2,139,996 Buchanan Dec. 13, 19382,199,415 Philipp May 7, 1940 2,287,203 Smith June 23, 1942 2,835,437Boynton May 20, 1958

